Flexible tubes

ABSTRACT

A flexible container comprising a flexible sidewall defining a conical tube which is open at one end wherein the sidewall has a section at the open end in which the tube has an expanded or increased diameter to thereby provide a section with the configuration of a truncated cone to facilitate stacking of a plurality of tubes one inside another.

' llnited States Patent [151 3,661,301 Umland 1 May 9, 1972 [5 FLEXIBLE TUBES [56] References Cited [72] Inventor: Roger Couland, Fontenay-aux-Roses, UNITED STATES PATENTS France 2,028,112 1/1936 Westin ..222/92 X [73] Assrgnee: Societe de Condltlonnement en Alumlnlum FOREIGN PATENTS OR APPLICATIONS Scal GP, Pans, France 22 Filed: Feb. 20, 1970 629'467 Italy [21] App], No; 13,111 Primary Eraminer-Robert B. Reeves Assistant E.\'aminer-Francis J. Bartuska Att0rneyMcD0ugall. Hersh & Scott [30] Foreign Application Priority Data Mar. 3, 1969 France ..6905587 1 1 ABSTRACT A flexible container comprising a flexible sidewall defining a h2 5il g 5;0 0 coniczil tube which is open atone end wherein the sidewall has It It d t [58] Field of Search ..222/92, 94, 105, 106, 107, he m w the has expanded or 222/206, 215; 220/97; 264/DIG. 41; 113/121 D increased diameter to thereby provide a section with the configuration of a truncated cone to facilitate stacking of a plurality of tubes one inside another.

6 Claims, 2 Drawing Figures PMEN TEDMAY 9 I972 3,661,301

INVENTOR. Roger Coujcmd BY 7W Dex-(4 03M HM Mvi Scam FLEXIBLE TUBES The present invention relates to flexible containers, and more particularly to a flexible conical container which can be stacked with a plurality of similar tubes one inside another.

Flexible metal tubes are well known for use in packaging as containers for toothpaste, foodstuffs and a wide variety of other materials. Such tubes are generally delivered for filling in the form of a cylindrical container which is open at the end opposite of the removable cap. However, tubes of the type described present transportation and storage problems in that, because of their flexible nature, they are easily deformed or crushed. One solution to these transportation and storage problems is to form the tubes so that the sidewalls have a cross section which is generally conical whereby the individual tubes can be stacked one inside another. It has been found that such stacks of flexible tubes are considerably less susceptible to deformation or crushing as compared to individual tubes forming the stack since the walls of the stacked tubes are substantially in surface contact each with the other whereby the sidewalls of adjacent tubes in the stack tend to reinforce each other.

However; the use of flexible tubes having a generally conical shape is not completely satisfactory. For example, flexible tubes of the type described are usually closed after filling by mechanical means, such as by folding the open end of the tube whereby the resulting folded surface seals the open end. However, if the tubes are to contain oily products, foodstuffs or the like, the use of mechanical means to close the filling end is frequently inadequate to provide a tight seal prior to use of the contents. Accordingly, it has been the practice to introduce a material which is compatible with the contents of the tube into the fold which closes the filling end. For this purpose, the inner surface of the tubes are frequently coated with a thin annular coating of a sealant, such as liquid rubber or similar material, which operates, after drying of the coating to fill any voids which may be created in the fold to thereby provide a tight seal in the fold.

While the annular sealant layer is usually quite thin(e.g. having a thickness of the order of about 0.3 mm), it serves to prevent stacking of a plurality of tubes in which the tubes comprising the stack are substantially in surface contact whereby the reinforcing effect described above is not obtained. Thus, the annular sealant layer prevents one tube from entering the end opening of an adjacent tube to the extent necessary to enable the walls to be in surface contact.

It is accordingly an object of the present invention to provide flexible containers which overcome the aforementioned disadvantages and which can be stacked to resist deformation and crushing.

It is a more specific object of the present invention to provide flexible containers which are capable of forming a tight seal when closed, yet can be stacked with their sidewalls substantially in surface contact to thereby form a reinforced stack of flexible containers for use in storage or transportation. Other objects and advantages of the invention will appear hereinafter, and, for purposes of illustration, but not of limitation, an embodiment of the invention is shown in the accompanying drawing in which;

FIG. 1 is a sectional view of a flexible container embodying the features ofthe present invention; and,

FIG. 2 is a stack of flexible tubes of the type described in FIG. 1.

The concepts of the present invention reside in a flexible container comprising a flexible sidewall defining a conical tube which is open at one end whereby the open end is adapted to receive material for filling the tube and is adapted to receive the opposite of another tube when a plurality of tubes are stacked one inside another. The sidewall defines a section at the end of the tube in which the tube has an expanded or increased diameter to thereby provide a section with the configuration of a truncated cone, the apical angle of which is substantially the same as the apical angle of the unexpanded tube.

In accordance with the practice of the present invention, the inner surface of the truncated cone section is provided with a thin layer of sealant material which serves to fill any voids which are created when the open end of the tube is closed, as by a fold, to thereby provide a tight seal. Thus, the expanded diameter of the truncated cone section allows another tube to be inserted through the open end and penetrate the tube to a depth sufficient to permit the walls to be substantially in surface contact.

In order to provide necessary clearance for the insertion of one tube inside another, the difference between the diameter of the truncated cone section and the diameter of the tube at the same point if the diameter of the tube were not expanded is at least equal to, and preferably greater than twice the thickness of the sealant layer. Thus, the diameter of the truncated cone section is expanded in an amount at least equal to twice the thickness of the sealant layer. In this way, there is provided sufficient clearance between the sidewalls of the tube at the open end to enable one tube to be inserted in another when the surface of the truncated cone sections have been coated with the sealant material.

In accordance with a preferred embodiment of the invention, the height of the truncated cone section along its axis is at most equal to the height ofa cap element on the end of the tube opposite the open end. Thus, when a plurality of the tubes are telescopically stacked one inside the other one tube can penetrate another only to a depth whereby the cap member of the inside tube abuts the closed end or shoulder of the tube within which it has been inserted, and the truncated cone section of the inside tube does not extend inside that of the outside tube.

Refering now to the drawing, there is shown in FIG. 1 a flexible container embodying the features of the present invention. The tube is defined by conical sidewall 1 and is provided with an opening 3 at one end thereof adapted to be used for filling the tube. The opposite end of tube 1 is closed by means of a shoulder member 6 which carries a cap member 2 releasably engaged with shoulder member 6. As is illustrated in FIG. 1, cap 2 is threadably engaged with shoulder member 6, although it will be understood that various other types of releasable engagement means may be employed in lieu of the threaded engagement illustrated.

The sidewalls of the tube at its open end define a truncated cone section 4 which is concentric with the unexpanded portion of the tube. As is indicated by this figure, the apical angle of truncated cone section 4 is substantially the same as that of the truncated cone defining tube 1 whereby the walls of the expanded truncated cone section are substantially parallel with the walls of tube 1.

The inner surface of truncated cone section 4 is provided with a sealant layer 5 which operates to fill any voids created when open end 3 of the tube is closed. It will be understood by those skilled in the art that the sealant layer 5 may be applied to the tube as it is formed, or it may be applied thereafter.

The flexible container of the present invention is preferably formed of a flexible metal, such as aluminum, lead, etc., although it will be understood that various other flexible materials, such as flexible plastics or the like, may also be used. The expanded truncated cone section of the tube at the open end may be provided by means of conventional equipment in which the sidewalls of a conical tube near the end thereof are expanded or increased in diameter to thereby provide the truncated cone section.

FIG. 2 illustrates a plurality of tubes 1, 10 and 20 of the type described in FIG. 1 which have been stacked one inside the other. As is shown in this figure, tube 10 is stacked inside tube 1, and tube 20 is stacked inside tube 10. When the tubes are in stacked engagement as is shown in this figure, the inside tubes preferably penetrate the tube within which they have been stacked to the extent that the cap member 17 of tube 10 abuts shoulder member 6 of tube 1 within which it is stacked. Similarly, the cap of tube 20 abuts the shoulder member of tube 10. To this end, the height L of the truncated cone section is preferably equal to or less than the diameter P representing the height of the cap member as it is carried upon the shoulder member. In this way the extent to which one tube penetrates the other can be conveniently regulated to avoid insertion of the truncated cone section of one tube of the truncated cone section of another tube in which the former is stacked It will be apparent from the foregoing that I have invented a new and improved flexible container which can be stacked for use in storage and transportation whereby deformation and crushing ofstacks oftubes are completely avoided.

It will be understood that various changes and modifications can be made in the details of construction and use without departing from the spirit of the invention, especially as defined in the following claims.

I claim:

1. A flexible container comprising a side wall defining a conical tube, said tube being open at one end thereof and having a truncated conical section integral therewith, with the truncated conical section having a sealant layer on the inner surface and a diameter expanded beyond the normal wall of the conical tube whereby the smallest diameter of the conical section is larger than the largest diameter of the conical tube to enable another tube to penetrate the container to a depth at which the walls of the tubes are substantially in surface contact.

2. A container as defined in claim 1 wherein the apical angle of truncated cone section is substantially the same as the apical angle of said conical tube.

3. A container as defined in claim 1 wherein the diameter of said section is expanded in an amount at least equal to twice the thickness of said layer.

4. A container as defined in claim 1 which includes a shoulder member at the other end of said tube, and a cap member mounted on said shoulder member.

5. A container as defined in claim 4 wherein said cap member is threadably mounted on said shoulder member.

6. A container as defined in claim 4 wherein the height of said section is at most equal to the height of said cap member. 

1. A flexible container comprising a side wall defining a conical tube, said tube being open at one end thereof and having a truncated conical section integral therewith, with the truncated conical section having a sealant layer on the inner surface and a diameter expanded beyond the normal wall of the conical tube whereby the smallest diameter of the conical section is larger than the largest diameter of the conical tube to enable another tube to penetrate the container to a depth at which the walls of the tubes are substantially in surface contact.
 2. A container as defined in claim 1 wherein the apical angle of truncated cone section is substantially the same as the apical angle of said conical tube.
 3. A container as defined in claim 1 wherein the diameter of said section is expanded in an amount at least equal to twice the thickness of said layer.
 4. A container as defined in claim 1 which includes a shoulder member at the other end of said tube, and a cap member mounted on said shoulder member.
 5. A container as defined in claim 4 wherein said cap member is threadably mounted on said shoulder member.
 6. A container as defined in claim 4 wherein the height of said section is at most equal to the height of said cap member. 